From mboxrd@z Thu Jan 1 00:00:00 1970 From: clemc at ccc.com (Clem Cole) Date: Fri, 27 Nov 2020 14:17:44 -0500 Subject: [TUHS] Why do compress(1) and pack(1) use the .Z / .z extension? In-Reply-To: References: Message-ID: I thought the gz was because dos voilf not tell the difference between Z and z which was strange of course since it stored it on 8 bits unlike rt11 which used RAD50 (5bits) sigh. On Fri, Nov 27, 2020 at 2:00 PM Warner Losh wrote: > > > On Fri, Nov 27, 2020 at 10:17 AM Clem Cole wrote: > >> >> >> On Fri, Nov 27, 2020 at 8:08 AM Hans Wennborg wrote: >> >>> I'm trying to find out why compress(1) uses .Z as filename extension. >>> >>> My theory is that it was inspired by pack(1), which uses the .z >>> extension. >>> >> Yes. >> >> >> >>> >>> However, I haven't been able to find any info on why pack(1) uses that >>> extension. Does anyone here know? >>> >> No idea - but yes, Zucker used a .z at Rand when he wrote. >> >>> >>> Some searching led me to [1] which is a man page for pack from AUSAM. >>> It's written by Steve Zucker in 1975, so perhaps the extension is z for >>> Zucker? >>> >>> Was Zucker's pack(1) the first, though? This message [2] talks about a >>> Bell version. >> >> Zucker wrote it at Rand - early/mid 1970s. IIRC, It was later included in >> the original Harvard USENIX tape in the 'Rand' directory. I believe that >> Rand Pipes (named pipes) are in the same directory. Although some of the >> Rand stuff was being shared by folks on the ArpaNet before USENIX existed >> and I think it made it to the wild before the first USENIX tape. >> >> It was really important back in the day. Remember RK05's are only 2.5M >> bytes - source archiving and packing files was pretty important given the >> cost / byte of disk. >> >> I think there may have been an early version @ BTL - PWB may have >> distributed it also, but I'm fairly sure it was the Rand code that started >> it. Noel might remember more than I. I'm 90% sure we had it at CMU before >> we got either PWB 1.0 or UNIX/TS from Ted -- I want to say it we had it on >> 5th edition but maybe not. >> >> One of the PDP-10 folks will need to chime in here. My memory is there >> was something like pack(1) on the CMU PDP-10s and 20s that I saw before I >> saw the UNIX tool [not sure why I think this, but it may have been SAIL >> program - I remember looking at a number of simple tools when I learn SAIL >> years and years ago - 74/75-ish]. IIRC they were not exactly the same >> format as the 10's were 36-bit words, stored 5 chars in a word, but it was >> the same idea. >> > > Regardless of the early history, this is why gzip files end in .gz and not > .z. The pack'd files were considered too prevalent at the time to crowd > into that name space, even though this happened maybe 12 years after > compress started to displace pack. > > Warner > -- Sent from a handheld expect more typos than usual -------------- next part -------------- An HTML attachment was scrubbed... URL: